Study : Comparative small RNA analysis of pollen development in autotetraploid and diploid rice


Comparative small RNA analysis of pollen development in autotetraploid and diploid rice
MicroRNAs (miRNAs) play key roles in plant reproduction. However, knowledge on microRNAome analysis in autotetraploid rice is rather limited. Here, high-throughput sequencing technology was employed to analyze miRNAomes during pollen development in autotetraploid rice. A total of 172 differentially expressed miRNAs (DEM) were detected in autotetraploid rice compared to its diploid counterpart, and 57 miRNAs were specifically expressed in autotetraploid rice. Of the 172 DEM, 115 and 61 miRNAs were found to be up-regulated and down-regulated, respectively. Gene Ontology analysis on the targets of up-regulated DEM showed that they were enriched in transport and membrane in pre-meiotic interphase, reproduction in meiosis, and nucleotide binding in single microspore stage. osa-miR5788 and osa-miR1432-5p_R+1 were up-regulated in meiosis and their targets revealed interaction with the meiosis-related genes, suggesting that they may involve in the genes regulation associated with the chromosome behavior. Abundant 24-nt siRNAs associated with transposable elements were found in autotetraploid rice during pollen development; however, they significantly declined in diploid rice, suggesting that 24-nt siRNAs may play a role in pollen development. These findings provide a foundation for understanding the effect of polyploidy on small RNA expression patterns during pollen development that lead to low pollen fertility in autotetraploid rice. Overall design: To investigate the miRNAs associated with the pollen development of autotetraploid and diploid (CK) rice, three pollen development stages, including PMA (pre-meiotic interphase), MA (meiosis) and SCP (single microspore stage), were selected to construct six libraries and sequenced by Solexa high-throughput sequencing technology.


Accession number Name Taxon